fix(HLS): Fix support for SUPPLEMENTAL-CODECS on EXT-X-I-FRAME-STREAM-INF (#7992)

Author: avelad

lib/hls/hls_parser.js

@@ -988,6 +988,31 @@ shaka.hls.HlsParser = class {
               new shaka.hls.Tag(tag.id, tag.name, newAttributes, null));
         }
         variantTags.push(...newVariantTags);
+
+        // Duplicate iFrame tags with supplementalCodecs
+        const newIFrameTags = [];
+        for (const tag of iFrameTags) {
+          const supplementalCodecsString =
+              tag.getAttributeValue('SUPPLEMENTAL-CODECS');
+          if (!supplementalCodecsString) {
+            continue;
+          }
+          const supplementalCodecs = supplementalCodecsString.split(/\s*,\s*/)
+              .map((codec) => {
+                return codec.split('/')[0];
+              });
+          const newAttributes = tag.attributes.map((attr) => {
+            const name = attr.name;
+            let value = attr.value;
+            if (name == 'CODECS') {
+              value = supplementalCodecs.join(',');
+            }
+            return new shaka.hls.Attribute(name, value);
+          });
+          newIFrameTags.push(
+              new shaka.hls.Tag(tag.id, tag.name, newAttributes, null));
+        }
+        iFrameTags.push(...newIFrameTags);
       }
 
       this.parseCodecs_(variantTags);